What You Should Know About Pregnancy

Learn about the relationship you have with your baby during pregnancy and learn how you can be healthy during pregnancy

What You Should Know About PregnancyLearn about the relationship you have with your baby during pregnancy and learn how you can be healthy during pregnancy

Gabrielle Revere

Another 5 percent of pregnant women develop dangerously high blood pressure, a condition known as preeclampsia. The placenta, the baby's lifeline, has low blood pressure and relies on the naturally higher blood pressure of the mother's body to pump in nutrients. If Mom's blood pressure can be made to rise even more, all the better: The fetus will get an even greater share. The placenta achieves this goal by producing a protein called sFlt1, which makes it difficult for a woman's body to repair old blood vessels and create new ones, according to new research by Ananth Karumanchi, M.D., a kidney specialist at Harvard Medical School. Women have 4 pounds of extra blood circulating during pregnancy, and they need those additional blood vessels to carry it. If they can't build them, their blood pressure will rise.

Most pregnant women respond to this unwelcome sFlt1 invasion by making a protein that promotes blood vessel growth, which soon stabilizes the pressure. But women who are obese, who already had high blood pressure, or who have some still-undiscovered genetic defect may develop preeclampsia, according to Dr. Karumanchi. That's why doctors test pregnant women's urine — if they find protein, it's a sign that the kidneys are malfunctioning and blood pressure is rising. If that happens to you, your doctor will monitor you carefully and perhaps even deliver the baby early to prevent you from suffering the worst-case scenario: seizures, organ failure, and even death.

But Dr. Karumanchi's research isn't all gloomy. He and his colleagues hope to find a way to block excessive sFlt1. Within 5 years, your child's attempts to raise your blood pressure may be in vain — at least until his or her teenage years.

[Round 3] Pulling Some Punches

I wouldn't want to leave you thinking there's no love or reciprocity in pregnancy. You just have to look hard. In the mid-1990s, Diana Bianchi, M.D., a professor of pediatrics at Tufts University School of Medicine, was trying to develop a new way to test fetuses for Down syndrome when she made an astonishing discovery: She found male stem cells in the blood of women carrying female fetuses. In each case, the cells were from an earlier pregnancy with a boy. Research has since proven that babies leave a part of themselves behind in their mothers, apparently for life.

Unlike the stem cells harvested from frozen embryos that have gotten so much press of late, these cells aren't politically or ethically iffy. They're already inside any woman who has ever been pregnant (even if the pregnancy ended in abortion or miscarriage). And they could be lifesavers. Fetal stem cells have been found clustered at brain and liver injuries in female mice, where they were apparently attempting to repair the damage. "It's certainly conceivable that eventually we will discover how to harness these cells," Dr. Bianchi says, turning them into molecular MASH units. Your son or daughter may someday give you renewed life, as you once gave life to him or her.

Unfortunately, fetal stem cells occasionally turn bad. If their genetic markers are very similar to those of the mother's cells, her immune system can go haywire, leading to autoimmune diseases like scleroderma, which causes hardening of the skin, cartilage, and other connective tissue. As scientists learn more about managing autoimmune diseases, however, they might start checking for the compatibility of cells between mother and child early in a pregnancy to identify which women need early intervention, says J. Lee Nelson, M.D., a professor of rheumatology atthe University of Washington.

For now we can't make decisions about what genes we'll pass to our kids or tell a selfish placenta to keep its proteins to itself. But we can use the emerging science to arm ourselves. Since your baby is going to take as much as he or she can, make sure you get the nutrients you need (see "Eating for Two"). And score some back rubs from Dad, since he's more implicated in your physical hardships than he may realize.

Then take a deep breath and accept that pregnancy is a skirmish that doesn't come close to ending at birth. My son, Max, who is now 9, still commands a breathtakingly disproportionate share of familial resources. Have you priced an Xbox lately? Or orthodontia? Still, as I fold his socks, make him breakfast, and play chauffeur, it's nice to know that someday his stem cells may save my life. I'm going to hold him to that. If you're ever pregnant, I advise you to place your hands on your belly and remind your growing baby that you expect the same. It's never too early to start instilling that sense of powerful obligation that every child should feel toward its mother. That's how, in the end, we wily moms always win.